Every year they issue a winter influenza vaccine instead of making vitamin D pills and artificial sunlight available. Young people never take the winter flu vaccine and are fine.
Vitamin D, part 3 – The Evidence
41–50 of 218 posts
Re: Vitamin D, part 3 – The Evidence
#42A couple years ago my blood tests showed low Vit D and so I've been taking it twice a week since. I don't know about health but on the two days I take it I seem to have a lot more motivation to get things done and instead of thinking "I should go do X" I find myself just doing it.
Re: Vitamin D, part 3 – The Evidence
#43Earlier quoted context omitted.
I would frame it in the opposite direction: having a serious illness is correlated with low levels of Vitamin D. People with a serious illness may stay inside more, and go outside less. It's possible that "low levels" of Vitamin D are still within the healthy range, and they merely are an indication of how much time the person has spent outside during the day. In other words, it's possible that Vitamin D is pure symp…
> It's not even necessarily the case that going outside is healthy, but that healthy people tend to go outside more. This is a departure from the discussion of supplementing vitamin D though, isn't it? I guess the treatment "go out and do sports" is a very different one compared to "X amount of vitamin D per day as a supplement" and the former may indeed be healthy , while the latter may not be, even though they both…
> This is a departure from the discussion of supplementing vitamin D though, isn't it?
I don't think so, no. If my hypothesis is correct, the problem is not that they didn't go outside and play sports. The problem is that they are sick, and sick people don't go outside as much.
Forget Vitamin D for a moment. Imagine that every time you were outside for an hour, the Outside Fairy granted you one Outside Token. Over the course of a month, it's reasonable to assume that healthy people would have more Outside Tokens than sick people. But these Outside Tokens obviously would have no causal effect on whether or not people are sick. Giving sick people Outside Tokens would obviously not help them - their problem is that they are sick. They have less Outside Tokens because being sick makes it more difficult to be outside for an hour.
In other words, the arrow of causation is being sick -> less Outside Tokens, and not being sick -> more Outside Tokens. If that's the case, then Outside Tokens are irrelevant to treating the sick people. If, say, they have cancer, you should ignore the Outside Tokens and treat the cancer with all of the standard means we have of treating cancer.
They hypothesis is that "low levels of Vitamin D" are just those Outside Tokens.
(Yes, when Vitamin D levels are low enough, that can cause other kinds of health problems. But this hypothesis is that what we're measuring as "low" is still within the healthy range. How do we know when it's not in the healthy range? When it tends to cause the kinds of problems we are more confident are directly linked to low levels of Vitamin D.)
Re: Vitamin D, part 3 – The Evidence
#44So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
> What is a reasonable hypothesis then?
The logical conclusion is that vitamin D, as we measure it, is proxying for another factor that we haven't yet detected. This X-factor is heavily influenced by sun exposure, but at most weakly influenced by vitamin D supplementation in its current form.
Analogously imagine that we had no concept of the health benefits of exercise. We detected that people with gym memberships were much healthier than those without. So, we try giving a bunch of people a free gym membership. Yet few of the recipients end up using it to do any exercise. In this case the supplement group would show nowhere near the health gains of the baseline gym members. The key issue is that gym membership is only proxying for the underlying X-factor of physical activity.
Michael Pollan makes a great critique of a type of thinking called "nutrionism". Basically that the determinants of health can be broken down into their isolated sub-components. "You need X amount of protein, Y amount of this vitamin, and Z amount of this mineral." The problem is that unless our understanding of biology is perfect, there's almost certainly going to be flaws in the decomposition. When we try to replicate a healthy diet with a synthetic mixture of vitamins and macronutrients, we still fall well short of natural food. A very famous example of this is when people on total parenteral nutrition kept dying, because the original formulations lacked chromium. Humans only need a microscopic amount, yet die without it. Nobody realized this because almost all natural foods have trace amounts that satisfy the requirement.
As for vitamin D specifically, I think there's three pretty good candidates for what the missing X-factor is. In order from least to most controversial:
1) Our current understanding of the sub-types of Vitamin D is not complete. It wasn't too long ago that we began to learn that Vitamin D3 is much more essential than Vitamin D2. It's possible that there are sub-types of Vitamin D3 that are made in the correct proportion in the skin, but aren't represented in supplements.
2) There are other micronutrients, not yet discovered, that are synthesized in the skin. This goes back to the chromium example. Sun-exposed people may have high levels of Vitamin D + Vitamin X. Yet we can only measure the former, so we over-attribute the importance of Vitamin D.
3) Sun exposure induces the same physiological adaptations as physical exercise. Consider what we know about the mechanism of how exercise induces its health benefits. Micro-traumas to the muscle fibers and metabolic stress leads to an acute stress response. That peak leads to a down regulation of the HPA axis with accompanying metabolic benefits. The muscles recover, with an adaptation against the stress.
Is it not possible that something similar happens when we sunbathe? Without a doubt UV exposure induces micro-traumas in the skin cells, that looks very similar to what's found in the muscle cells. There's also emerging evidence that sun exposure triggers the HPA stress response[1], in the same way that exercise does.
If this is the case, then trying to replicate the benefits of sun exposure with supplements is a fool's errand. It's the sun exposure itself, specifically the sun damage, that is directly responsible for the health benefits.
Re: Vitamin D, part 3 – The Evidence
#45So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
It might just be that the production of vitamin D via sunlight has other effects on the body, perhaps vitamin D has been a proxy for those effects but for obvious reasons taking it as a supplement doesn't trigger the same outcome. It's unfortunate that exposure to UV is so harmful, I'm left wondering if trials using UV lightboxes to stimulate vitamin D production would change the kinds of outcomes (cancer, heart dise…
It's possible, but we have no positive evidence for it. Absent that evidence, I don't think we should assume that possibility is reality.
Re: Vitamin D, part 3 – The Evidence
#46Shouldn't they be looking at getting vitamin D via sun exposure, rather than supplementation? If the real benefit is sun exposure, which also increases vitamin D, then just supplementing vitamin D won't show any benefits.
Very hard to quantify sun exposure and do this in a controlled way.
Very hard? Sounds one of the easiest things to measure and control for...
Tack a sensor (e.g. watch like) to people working outside, vs people working inside, inmates, etc for example...
Check people in long norther nights vs the carribean (you can find lots of people of either place in the other).
Re: Vitamin D, part 3 – The Evidence
#47I've seen a well explained video about a study[1] saying vitamin D3 helps in reducing severity of COVID19. What's your argument(s) against it?
Re: Vitamin D, part 3 – The Evidence
#48If deficiency is linked to all these maladies then why aren’t we seeing them occur with less frequency in areas that get full sun year round?
With some exceptions, in general we're much likely to be indoors nowadays than say... 300 years ago, regardless of how much sunlight is available. But it is hypothesized that people of color see higher frequencies of epithelial related diseases (high blood pressure, heart disease) because we're mostly indoors nowadays and the shorter stints outside aren't long enough to absorb enough sunlight through darker skin. Epidemiologists have typically assumed this is due to socio-economic reasons, but even in affluent black communities, we're still seeing outsized incidences of these disease than in "lighter shade" communities.
Re: Vitamin D, part 3 – The Evidence
#49For other reasons I get tested for vitamin D every few months and managed to get my levels just above the normally recommended amount as per doctors advice. When people are saying they’re taking 25-100k UI a day I’m just stumped why they’d be doing that without medical advice, the amount to change my levels was nothing in comparison.
That's a dangerous amount. Vitamin D is a hormone and shouldn't be taken willy nilly. If you know anyone doing that you should warn them to stop.
Re: Vitamin D, part 3 – The Evidence
#50I've seen a well explained video about a study[1] saying vitamin D3 helps in reducing severity of COVID19. What's your argument(s) against it? [1] https://www.youtube.com/watch?v=V8Ks9fUh2k8
To add to your question, here is the latest study that was linked here last week...
https://www.sciencedirect.com/science/article/pii/S096007602...